Equity Method and Other Investments - Yaskawa Brooks Automation, Inc. (Details) - USD ($) $ in Thousands		12 Months Ended
	Mar. 20, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Goodwill		$ 233,638	$ 202,138	$ 121,408
Equity in earnings (losses) of equity method investments		9,381	2,380	(164)
Yaskawa Brooks Automation, Inc.
Schedule of Equity Method Investments [Line Items]
Joint venture interest (as a percent)					50.00%
Final dividend				1,800
Liquidation costs				200
Equity Method Investment, Other than Temporary Impairment				700
Equity in earnings (losses) of equity method investments				(600)
Amounts receivable		0	0
Amounts owed		$ 0	$ 0
Equity Method Investee | Yaskawa Brooks Automation, Inc.
Schedule of Equity Method Investments [Line Items]
Revenues earned from joint ventures				2,500
Charges for products or services				$ 700
Yaskawa Brooks Automation, Inc.
Schedule of Equity Method Investments [Line Items]
Total purchase price	$ 1,800
Goodwill	$ 200